Resonance Raman investigation of meisenheimer complexes derived from 1,3,5‐trinitrobenzene

Abstract

The Raman spectra of Meisenheimer complexes derived from 1,3,5trinitrobenzene and proline, tryptophan, albumin and pyrrolidine were obtained. The spectra excited in and out of resonance with the electronic transition at ca. 460 nm show an outstanding enhancement of modes involving mainly the symmetric stretching and deformation of the NO, groups. The results also indicate a marked reduction in the symmetric and asymmetric stretching frequencies, in addition to suggesting a decrease in symmetry on going from the parent nitro aromatic to the Meisenheimer complexes.

The solubility and recrystallization of 1,3,5-triamino-2,4,6-trinitrobenzene in a 3-ethyl-1-methylimidazolium acetate–DMSO co-solvent system

“…The peaks observed at 807 and 1149 cm À1 correspond well to a previously reported signature of a s-complex. 14 The formation of a s-complex with TATB was described during the synthesis of TATB by the vicarious nucleophilic substitution of hydrogen. 15 Selig also assigned the absorption band at 409 nm to a s-complex between strong bases and TATB.…”

Raman spectroscopy

“…However, a timely review has appeared relating to the use of RR in the analysis of electronic and molecular structures of conjugated polymers (444) which contains much information relevant to RR studies in general. Other applications of RR not discussed elsewhere relate to the identification of chromophore states in allophycocyanin and phycocyanin (445), an overview of far ultraviolet RR spectroscopy (446), a study of the Meisenheimer complexes of 1,3,5-trinitrobenzene (447), and azo dyes (448). As with most other sections in this review there has been activity in the area of NIRFT Raman spectroscopy, and resonance enhancement of the bacteriorhodopsin Raman spectrum has been reported (449).…”